Linc@ScootaCo

21 December 2010

I have been speaking to a lot of customers lately regarding their brakes and how to care for them, use them and ultimately get the best performance out of what has been fitted to their scooter or bike.

Scooters and motorcycles generally use two different types of brakes or more commonly a combination of the two;

Example of the inside of a drum brake

The first and most common is the Drum Brake it is very simple and very effective within limits such as cost of production, wet or dry operation and size and weight of machine. Effectively the drum brake as suggested by the name is a pair of matching (or slightly smaller diameter) shoes which are fixed to the front fork or rear engine case/swingarm, the “drum” is fixed to the wheel hub and sits over but away from the shoes, when the brake lever is applied a small flat cam lever rotates forcing the shoes outwards and against the inside of the drum creating friction and ultimately slowing the rotational speed of the wheel until completely stopped or under light applications until the desired speed is reached.

Disc brake on the front wheel of a scooter

Disc Brakes work under a similar theory. In place of the drum is a flat disc of usually 3-5mm thickness which is attached to the wheel hub with the calliper being attached to the fork or engine casing/swingarm. When the lever is actuated it forces a pair of brake/friction pads hard up against the disc and creating the same stopping effect as the shoes do in the drum brake.

Both disc and drum brakes have some inherent advantages and disadvantages. Drum brakes are very easy and cheap to manufacture and work very effectively on a lightweight machine in dry conditions. The linkage system can be very simple and pretty much trouble free as it is usually a direct mechanical linkage or cable so very little to go wrong. The down side is once (as any postie will know about this if they rode the old P Model CT110) the drum has worn past its serviceable limit, ie; the diameter has worn past the outer diameter, there is very little to be done except replace the drum. The problem is it is usually integral with the rest of the wheel and therefore not a cheap exercise. Most wheels will go through at least 5-6 sets of shoes before this ever occurs and very possibly will outlast the rest of the bike. Drum brakes are also prone to squeaking. This is caused by a build up of all the old friction and drum material within what is a mostly closed environment getting caught between the two components. Brake squeak is pretty much an aesthetic annoyance more so than a safety issue. The main downside to drum brakes is that should they become totally immersed or have water get into the contact areas your braking performance is significantly reduced (yet again ask any postie or old school dirt bike rider about stopping after a creek crossing).

Disc brakes have classically always been more expensive to produce mainly due to the complex mechanics of the hydraulic actuation. Unlike the drum brake the pads within the calliper are forced against the rotating disc via a high pressure pump or master cylinder as it is known. This inturn forces the piston/s inside the calliper against the pad and creates massive clamping pressures and a much stronger stopping action. Because all the friction surfaces are mainly exposed cooling is far more efficient (have a close look at the wheels next time you see a V8 supercar or F1 car in full deceleration in a race-they glow red hot and in fact rely on this massive heat to work properly) and again due to the exposed components any water/mud or contaminates splashed against the disc are very quickly dissipated by the wiping action of the leading edge of the brake pad. Most disc brakes will still work very well even totally immersed. If you look after the hydraulics with a fluid flush every 1-2 years the cost of replacement discs and pads is considerably cheaper as they can be replaced independently of the wheel/hub.

The best way to care for the standard brakes on your scooter is to always ensure your adjustment on drum brakes is up to spec. Don’t wait till the lever is hitting the bar before adjusting or getting a mechanic to do so. Try to avoid getting foreign material in to the hub area - stay away from extreme environments. Most scooters are not dirt bikes or submarines! If you have a new set of shoes fitted and half of your adjustment is gone before correct adjustment is achieved this is an indicator of worn drum area.

Disc brakes will withstand harder environments over drum brakes, but as suggested previously this not a licence to go off-roading. Brake fluid is hygroscopic (it attracts water out of the atmosphere) and therefore must be flushed at least every 18 months to two years. Keep an eye (or your mechanic should if you get regular services) on the thickness of the brake pad material and change them when they get low- you do not want metal to metal! This destroys the disc and these are generally not cheap.

If you’re worried about your brakes, or want them checked out and serviced, book into your local scooter mechanic asap. Afterall, they’re high up on the list of things you want to be reliable!

25 June 2010

All tyres have a finite life span. Like batteries, tyres do not like to sit idle for long periods of time and require attention on a regular basis. With everyday running around they will be worn down to the minimum wear level indicators the all tyres approved for Australian road use have on them. However the road is not the only contributing factor to wearing your tyres out in kilometres, or for higher spec tyres, the length of time they have been used.

The average small volume scooter tyre will loose approximately 2-5psi every month and therefore require inflation to their recommended pressure during this time. We recommend every second tank of fuel is a good rule of thumb or alternatively once a month. The pressure to run in them is generally 30psi front and 30-35psi rear depending on the load your scooter carries - like riding two up or hauling a big load of groceries etc.

If your tyre pressure is too low it causes the tyre to bulge out and flex at the road surface contact point. If the speed is elevated this happens approximately 1-2 times per second (every full rotation). Two things will then happen; the tyre temperature dramatically increases and the chords that make up the case construction weaken and can separate - causing a blow out or at the very least poor road holding and tyre wear. Or if you are tubeless (and that is just about all late model scooters) you also risk rolling the tyre bead off the rim causing loss of pressure very much like a blow out. Having experienced this in person it is not a lot of fun and can cause loss of control.

Front tyres do not “wear out” as frequently as rear tyres as the weight distribution on a scooter is biased towards the rear. Front tyres should be replaced around every two years due to deterioration of the rubber and casing materials. Rubber will perish and harden during this time causing fractures under use.

Tyres also have a cycling life. This is the amount of times the construction materials (primarily the rubber) can be heated and cooled. For example; a race slick used by the professional racers only have a cycle life of 5-10 times and are usually replaced every race, as opposed to a long range touring tyre which may have 500 - 1500 cycles - bearing in mind they should see 6,000 - 10,000kms on average. The obvious difference between the two is their intended application; the race tyre is very soft designed to give maximum grip even at extreme lean angles at the expense of rapid wear, while the touring tyre is much harder - giving longer miles and better wear but you will not get the traction the race tyre can give. In other words don’t go out and try to get your knees and elbows on the deck through corners on the road/tour type tyres.

I have a theory on budget tyres which runs along the old “you get what you pay for!” Recognised quality brand tyres may cost an extra $10-$50 at fitting but generally return better performance in both roadholding and long term wear. Join it with the fact they can be repaired should you suffer a puncture (which they tend to be more resistant to as well) the cheaper tyres do not stack as well over the life of the tyre.

The average stock we keep for scooter tyres - mostly Pirelli and Maxxis

25 March 2010

Batteries in scooters have a high attrition rate! This can however be minimised through an understanding of what it does and how it lives.

I will write about small capacity Scooter batteries (50cc) as they are most prone to failure. The average 50cc scooter runs a very small 4-5amp hr battery in comparison the average small car which runs a 20-30 amp hr battery. The average 50cc scooter when running only creates a usable charge adequate for any sort of re-charge from 50-100% throttle opening. By comparison even a small car with headlights on will create an effective re-charge at idle or above. What this means on the road is you would almost have to ride your 50cc from Cairns to Townsville non-stop at 100% throttle opening to effectively re-charge a flat battery.

The size difference from car to scooter batteries

In an effort to provide owners as much power as possible the Alternator in a 50cc is built as lightly as possible to minimise mechanical drag. A car by comparison charges at a much higher amperage rate (they take into consideration the maximum running load a car may have to provide - stereo, air con, high beam, indicators, and horn all operating at once). This is why a good indication of impending battery failure in a scooter is the horn and indicators doing funny things while at idle – aside from the fact you had to kick start it!

If a scooter is ridden regularly and is in good health ie; starts within 1-2 seconds of cranking the charge rate even on a short run is enough to replenish this depletion.

The battery will generally last at least 18 months to 2 years if it is a good quality maintenance free type, or level checked regularly if maintenance type.

Even sitting on a shelf a fully charged 4-5 amp hr scooter battery will self deplete within 3-4 weeks. Compound this with the inherent current draw of a scooter wiring harness (particularly if it is a Chinese scooter with the good for nothing “it will look good in the brochure” add on bell and whistle security system) and this can be as low as 1-2 weeks. Compound this again with a massive cold cranking effort due to the carburettor drying out and 10-15 seconds worth of engine vacuum alone required to prime the fuel system, the battery will just give up.

Every manufacturer will state in their owners manual that any scooter left for more than 5-7 days should be kick started at this time for this reason, it is also something sales people should stress on the delivery of any new or used scooter but rarely ever is.

If a scooter is used only intermittently (our Navy customers know of this, due to extended sailing times) the best advice is to fit the $65.00-$80.00 smart charger, it is cheaper than a replacement battery and emulates the charging cycle of a routinely ridden scooter. It works as follows; a small set of leads are attached to the battery via the clamp bolts, the lead is then run out through an access to a nondescript location (under body work away from hot or rotational mechanical components), this loose end has a one way male/female plug which has a matching plug which goes by a longer lead to a power pack that plugs in to your 240v house socket. The leads are usually long enough to reach a convenient outlet in the garage. What this unit does when switched and left on is monitor the battery level constantly and charge it as required when the level drops enough (5-10%) it will then turn itself off and stay dormant until again the level drops. These units will generally double the batteries life and it can be fitted to your next scooter and so on.

The Battery Fighter Junior - tried and tested by our Navy customers

A battery will fail primarily due to a powdery substance (Sulphate) which is a chemical by-product of electrolyses (battery discharging/charging). Sulphate collects in the bottom of each battery cell (6 of these in a 12 volt battery) and if left in this state or if the battery was rapidly discharged (see scooters sitting for extended periods) it can then create a dead short between the insulated lead plates inside, this is referred to as “dropping a cell” this is generally an unrecoverable state for a battery and is cause for replacement/disposal, if a battery has discharged over a long period from sitting it may be savable by re-charging using a low amperage deep charge (usually overnight or 12 hours) but every discharge will on average cause an efficiency loss of 5-15% every time.

At ScootaCo we will wet down and charge your battery just prior to delivery, so just like Maccas you are getting the freshest possible battery (that’s maybe not the best analogy), not one that has been sitting on the shelf for six months and by that stage possibly not much better than the one it replaces. We do need at least 30 minutes to allow this so please ring ahead or come back and pick it up after this time, all our batteries are dated the day they are wet down so they can be chronologically monitored.

Even though two stroke scooters and motorcycles are on the “way out” – they are still, for the time being at least, in the 50cc market the engine type of choice for the majority of scooter manufacturers. This is with good reason;

they produce good power to weight ratio for their capacity

they are inherently simple in design; and subsequently

economical and easy to fix

Due to their sometimes quirky and temperamental personalities (and yes anyone who has owned one will know what I mean by this) two strokes (2T) are up against stiff opposition with the modern four stroke (4T) design which has come along in leaps and bounds in the last 5-10 years.

The biggest concern with 2Ts and where a lot of their “multiple personalties” are derived from is due to the quality of the oil which is used. 2T engines use their oils differently from a 4T in that the oil is mixed with the fuel and is burnt as part of the combustion process. This is called a “total loss system” due to the fact once it is burnt it is gone. Alternatively 4Ts circulate the same oil throughout the engine continuously which is then (or should be) routinely changed.

“Why the then do we need a good quality oil if it just gets burnt?”

Like the oil in your car, motorcycle or any 4T engine, the 2T oil is used as a lubricant as it passes through the major engine components on its way to the cylinder and piston before being burnt and discharged, commonly known as the “Blue Smoke” seen blowing out your exhaust.

The "blue smoke" syndrome. Photo owned by nualabugeye@flicker.

In the old days the oil was mixed at a set ratio with your fuel and then put into the main fuel tank and metered through the carburettor. This method was messy and fraught with danger in that if you got the ratio wrong major engine damage could result if to lean (too little oil) or a succession of fouled spark plugs if to rich (too much oil). These days however all 2T machines run an oil injection pump which meters and injects the oil at the correct ratio relative to engine speed and throttle position. This system however is not perfect and like the old premix engines has its share of anomalies as well.

Getting back to how the oil quality affects your engine; again in the old days 2T engines were big old “agricultural” things - big lump of slow revving piston, thick piston rings, open exhaust port with a basic or no inlet reed valve. What this meant was the engines were under stressed and could afford to run a bit of variance in oil quality and the aforementioned fuel/oil premix ratio and still survive.

“CARBON!!”

The nemesis of all 2T engines, it is an unavoidable by-product of 2T combustion and like ash in the bottom of a wood barbeque is what is left of your oil once it is burned. Old school 2Ts (eg Vespa, Lambretta, old European motocross bikes, etc) are not overly affected other than clogging up the exhaust pipe or expansion chamber (Invite your mates over to use that aforementioned BBQ, throw it on after the steaks were cooked and ‘problem solved!’).

The modern high performance 2T (and yes that does include the humble 50cc scooter) are a totally different animal! They now rev very high for sustained periods. This is achieved through much lighter reciprocal masses ie- pistons, con rods, crank shafts etc. The pistons run a very thin piston ring(s) which are prone to jamming in the piston ring grove as carbon builds up. This in turn causes the engine to create a double edged sword with poor primary and secondary compressions. Primary compression being under the piston in the crankcase, which is then transferred to the secondary compression area being above the piston in the main cylinder area - As suggested when one is gone it also affects the other.

Most manufacturers suggest a 10,000klm de-coke service; the cylinder and piston are removed, the rings taken off the piston, and all carbon being physically removed via a mechanical method - usually a sharp scraper and an apprentice.

Like most service industries a technicians labour time is expensive and it has now become a more practical option (on a fifty at least) to just replace the piston and rings, take steps to either avoid it or at least delay it as long as possible. This is where the modern full synthetic 2T oils become so important. If from new these oils are used the 10k de-coke service can now be done at 20,000klms. Do the math it works out as follows.;

10k De-coke service (just T/E not routine items) $350.00

If new piston and rings required $450.00

Alternatively;

Synthetic 2T oil average per litre $ 20.00

Mineral (or lower grade) $13-$18 $15.00

If the average scooter uses 1 litre per 1000klms synthetic oil costs $200.00 per 10K. Mineral or lower grade costs $150.00 for the same distance travelled. The price difference over 20,000klms in oil is $100.00 however the same de-coke servicing costs are $450.00 less due to the increased mileage gained by using a better grade of oil.

This does not include larger ticket items like replacement crankshafts (burn one of these out on the average late model 50 and the repair cost = throwaway)

The last but not least problem with modern 2Ts is that the exhaust pipes now all have catalytic converters in them. I often use an analogy where catalytic converters in 2Ts are “a bit like trying to spit a mouthful of porridge out the kitchen window with a fly screen on it!” This is because in an effort to make 2T engines compliant with current emissions laws they must have one.

A catalytic converter or “cat” is a rolled up mesh of wire which essentially allows the noxious gasses to pass through where they react with properties within which render the gases less harmful to the atmosphere. This is great in a working 4T where the engine is not burning oil as part of the process. However our old enemy the “Carbon” has a nasty habit of clogging up the fine galleries which are the “Cat”. Using synthetic oils (like the deposits on piston rings) will reduce the rate at which this happens.

Yet again falling back to the economics of it, the average OEM pipes (factory original) usually start at $600.00 dollars to replace, with some up around $1200-$1400.00. Unlike the old school BBQ cook up you can not burn out the carbon deposits as you will destroy the somewhat sensitive Catalytic mesh material or at the very least melting it into an outlet clogging blob.

To finish up: a life story of the average 50cc 2T scooter

In an effort to keep the ever increasing costs of commuting to work “Customer X” will buy a new shiny scooter. The Commodore or 4WD can now be parked up and used on wet days or weekends. It is an exciting time and Customer X listens intently while the importance of the modern 2T oils virtues are extolled. With hand on heart Customer X promises to get it serviced by the book and never use any oil other than that recommended by the staff at point of sale/delivery. Customer X has done their homework they have bought a good quality scooter, which while under its warranty period is receiving the recommended servicing and same oil. This goes on for the first 18 months to 2 years.

If the scooter bug bites hard the love will continue and more than likely a bike licence is obtained and a larger capacity scooter is then a natural progression. A new love is on the scene and the old love (50cc 2T) is sold to help finance this “new excitement”. Customer X loves scooters so much now the next door neighbour/friend/work acquaintance has picked up on this and becomes the next proud owner. Customer X does not “extol the virtues” of the modern synthetic oil quite as strongly as the original sales person. Besides the scooter is now outside its warranty and Customer Y’s dad/grandad/personnel trainer used to have this Magic Mineral 2T Oil that he used to use in his Victa/Mercury outboard etc and its only $9.95 a litre so in it goes.

Three to four months later the low oil light starts to flash on the way home but its been a long day so Customer Y gets home goes inside and relaxes. A couple of days later the oil light is now on solid (that is Danger Zone), Grandad is busy out grey nomading around the countryside and is not easily contactable regarding the Magic Oil so something has to be done. “Oh look there is a “BP servo!” Sure enough Zoom outboard oil is available so in it all goes and its only $11.95 a litre.

Another three months go by but this time the available servo is a Caltex. They have 2T oil but it’s for mowers and whipper snippers so in it all goes. Because Customer Y remembers Customer X’s advice that was something about “synthetic oils” this one will be okay because it is Semi Synthetic and besides it is $14.95 a litre so it must be good.

This is bad, repeat, BAD!!

Another three months go by the scooter is pretty much just a tool now and all Customer Y’s mates have borrowed it here and there. It’s getting a little worse for wear also getting hard to start. “That must be because it needs a general service!” so the repairer/service agent is called and the routine service is booked albeit 4-5000klms overdue but hey it’s a 2T! It’ll be right - it still runs.

What I have described here is what I call the “Oil Cocktail” and like those of the Molotov variety are a deadly brew. In the oil world Mineral, Semi Synthetic and Full Synthetics DO NOT MIX. The reason for this is because the base elements the oil starts life as are not compatible – not even within the same brands (ie Shell, Castrol, Motul etc). Worst case scenario they can “gel up” creating blockages within the injection system similar to hardening of the arteries. At the very least mixing oils will in fact “promote” carbonisation of the critical components. Outboard oils have additives which are designed to minimise carbon in lower operating temps (in an outboard the whole sea is your radiator). It also has additives to neutralise water should it find its way into the premixed fuel or injection reservoir. Whipper snipper/mower oils have different additives particular to their application.

If it is caught early enough the oil mixture can be drained or extracted and the correct quality and application of oil put back in the damage will be minimised, avoiding the need for a top end rebuild.

At ScootaCo we do our best to provide our clients with the most economical transport solutions possible; by this we mean the best quality scooters, the least possible down time, fuel economy with this form of transport is a given. This does not suggest our scooters or our hourly rate for labour are the “cheapest” they are however going to return the best possible dollar per mileage ratio by virtue of quality.

ScootaCo technicians regularly attend training courses on our product and are all enthusiasts in this type of product. What this means to our clients is they have people working on your scooter who are genuinely interested in what you ride and how you ride it and what this means to them when they are servicing or repairing your machine.

When you book your machine in with us all staff are trained to ask questions. These will usually start with “how many kilometres?” or “how long since the last service?” which will then lead us into more specific questions regarding what will be required on that particular service.

The ScootaCo Workshop; end of day - everyone has gone home.

A quick couple of tangents - all scooters have a recommended kilometre or time based service schedule. A big kilometre rider will require routine servicing on a regular basis due obviously to the high kilometre usage. We have one owner with a 125cc machine which is clocking 15000 kms or more every 6 months: this is “big kilometres”. The flip side of this is the city commuter/rider who lives 2-3 kms from home to work and clocks less than 2500kms per year. They will still require regular servicing due to the short stop start riding and general deterioration of fluids and rubber etc.

To define “Service”; this is routine attention to items that are either wear and tear or require regular adjustment. If your bike is making funny noises has poor performance or a myriad of other symptoms this is then regarded as “Repair”. This is not to say that a “serviceable” component is not contributing to this type of anomaly, however if the bike is receiving “regular scheduled service” this is generally not the case.

Services are usually able to be in and out within a morning or afternoon (worst case scenario in early AM-out PM). We also do offer our rental Zip50 at $25 for that period which is cheaper than a Taxi return and allows you freedom to get out at lunch if need be. Most routine services are also able to be estimated to within $20 dollars prior to commencement of work. Your owner’s manual will give the schedule for your particular scooter. General rule of thumb is however 50-200cc machines every 2,500kms or 8-12 months - whichever comes first.

This is a repair. Photo owned by PJ Chmiel.

Repair work is a different as due to the unpredictable nature of mechanical repairs and parts supply can be very hard to determine what is required until identification and/or diagnosis of the fault can be performed. Like most service type entities we charge by the hour to perform this with most diagnosis taking at least 30 mins at $90.00 per hour + sundries. This is usually a minimum of $50.00 then of course the hourly rate to repair that fault once identified. Again we pride ourselves on being accurate in this regard and can generally get to within $50 of the initial estimate on repair completion.

We do make every effort to contact our customers should we find hidden repairs once work has commenced and subsequently ask for confirmation to proceed beyond that point. We can also provide recommendations for further repairs based on a Priority versus Budget basis at any time a bike is in our workshop.

Like a Doctor’s surgery we work on getting machines in and out at the promised times so we do ask people to call and re-book if they are unable to make the agreed appointment time. We are generally able to shuffle smaller jobs around on any given day so running a little late does not necessarily mean we will not get the bike in and out on that same day.